Using a simple external teach mode and polarization filter, the devices can be adjusted to accurately sense a wide range of clear objects as well as translucent or opaque objects through a transparent medium. Even high-quality optical glass can be detected at any distance within its 4 m range. With a short response time of less than 2.5 msec, the units can detect fast-moving objects. A wide dynamic range allows them to adjust automatically and maintain accuracy in heavily contaminated lens conditions. The die-cast zinc housing measures 50 x 50 x 1.54 mm and is IP67 sealed for harsh environments.